Field of the Invention
The invention relates to a containment spray system for a light-water reactor, having a water trough in a safety tank and having a spray branch, a pump and an outlet-side spray nozzle array, connected to the water trough, for injecting water into the containment in finely dispersed form in the event of an operational incident.
One such containment spray system is known from German Patent DE 22 07 870 C3, corresponding to U.S. Pat. No. 3,966,548. In that system, the water trough communicates with a sump cooler disposed in the containment through supply and drainage lines. Accordingly, not only trough water but water from the sump cooler as well is used for the spraying.
Such containment spray systems have the task of spraying water being aspirated through a pump, in finely dispersed form in the safety tank, in order to allow both the temperature and the pressure in the safety tank to be reduced and also to allow radioactive aerosols, which form inside the safety tank to be bound, in an incident that cannot reach the outside. Containment spray systems like that referred to above, which aspirate the spray water from the sump of the safety tank, cannot spray with the desired fineness because if the return cooling water and emergency core cooling water fed into the primary loop during the incident is returned to it, the sump can contain contaminants or impurities that can stop up the nozzles.
Published Japanese Patent Application 60-31092 describes a spray apparatus for a nuclear reactor with a pressure vessel. The pressure vessel is surrounded by a safety tank in which two water-filled chambers are present below the pressure vessel. The spray apparatus is disposed both on the walls of the safety tank and on a ceiling of the water-filled chamber. The spray apparatus on the safety tank wall is supplied with water from the chamber or from an additional tank located outside the safety tank through a pump, which is disposed in a separate chamber outside the safety tank.
German Published, Non-Prosecuted Patent Application DE 33 02 773 A1, corresponding to U.S. Pat. No. 4,587,080, describes an emergency core cooling system for a pressurized water nuclear reactor plant. The emergency core cooling system has a building spray pump that communicates with a fuel exchange and water storage tank. Through the emergency core cooling system, if an elevated pressure occurs in the reactor building, water is sprayed in through a spray apparatus on the ceiling of the reactor building. The water is pumped to the spray apparatus from an emergency water storage tank located inside the reactor building or a water storage tank located outside the reactor building through a pump, in particular a low-pressure pump. The pump is located in a directly attached structure outside the reactor building.